Next and break statements in R Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of loop with next statement

What is the output of the following R code?

R Programming

result <- c()
for(i in 1:5) {
  if(i == 3) next
  result <- c(result, i)
}
print(result)

A [1] 1 2 4 5

B [1] 1 2 3 4 5

C [1] 1 2

D [1] 4 5

💡 Hint

The next statement skips the current loop iteration when i equals 3.

The loop adds numbers 1 to 5 to the result vector except when i is 3. The next statement skips adding 3, so the output excludes 3.

❓ Predict Output

intermediate

Output of loop with break statement

What is the output of this R code?

R Programming

result <- c()
for(i in 1:5) {
  if(i == 4) break
  result <- c(result, i)
}
print(result)

A [1] 1 2 3 4

B [1] 1 2 3

C [1] 4 5

D [1] 1 2 3 4 5

💡 Hint

The break statement stops the loop when i equals 4.

The loop adds numbers 1, 2, and 3 to the result vector. When i reaches 4, break stops the loop, so 4 and 5 are not added.

🧠 Conceptual

advanced

Effect of next and break in nested loops

Consider the following R code with nested loops. What is the value of total after running it?

R Programming

total <- 0
for(i in 1:3) {
  for(j in 1:3) {
    if(j == 2) next
    if(i == 2) break
    total <- total + i * j
  }
}
total

A 12

B 9

C 0

D 16

💡 Hint

Remember next skips the current inner loop iteration; break stops the inner loop when i is 2.

For i=1: j=1 adds 1*1=1, j=3 adds 1*3=3 (j=2 skipped), total=4. For i=2: break stops inner loop immediately at j=1 (no addition). For i=3: j=1 adds 3*1=3, j=3 adds 3*3=9 (j=2 skipped), total=16.

🔧 Debug

advanced

Identify error in loop with next and break

What error does this R code produce?

R Programming

for(i in 1:3) {
  if(i == 2) next
  if(i == 3) break
  print(i)
  next
}

A Runtime error: infinite loop

B SyntaxError: unexpected 'next'

C No error, prints 1 then stops

D Error: object 'i' not found

💡 Hint

Check how next and break work inside the loop and their placement.

The code prints 1, skips 2, and breaks at 3. The last next is redundant but valid. No error occurs.

❓ Predict Output

expert

Output of complex loop with next and break

What is the output of this R code?

R Programming

output <- c()
for(i in 1:6) {
  if(i %% 2 == 0) next
  if(i > 4) break
  output <- c(output, i)
}
print(output)

A [1] 1 3

B [1] 1 3 5

C [1] 1 3 5 6

D [1] 1 2 3 4

💡 Hint

next skips even numbers; break stops loop when i is greater than 4.

The loop adds odd numbers less than or equal to 4. When i=5, break stops the loop. So output is 1 and 3.

Practice

1. What does the next statement do inside a loop in R?

easy

A. Skips the current iteration and moves to the next one

B. Stops the entire loop immediately

C. Restarts the loop from the beginning

D. Exits the current function

Solution

1. Step 1: Understand the purpose of next

   The next statement is used to skip the rest of the current loop iteration and continue with the next iteration.

2. Step 2: Compare with other statements

   Unlike break, which stops the loop completely, next only skips to the next round.

3. Final Answer:

   Skips the current iteration and moves to the next one -> Option A

4. Quick Check:

   next skips iteration [OK]

Hint: Remember: next skips iteration, break stops loop [OK]

Common Mistakes:

• Confusing next with break
• Thinking next restarts the loop
• Believing next exits the function

2. Which of the following is the correct syntax to skip the current iteration in a for loop in R?

easy

A. skip

B. continue

C. break

D. next

Solution

1. Step 1: Recall R loop control keywords

   In R, the keyword to skip the current iteration is next. There is no continue keyword in R.

2. Step 2: Identify correct keyword

   break stops the loop, skip is not a valid keyword.

3. Final Answer:

   next -> Option D

4. Quick Check:

   Use next to skip iteration [OK]

Hint: Use 'next' to skip, not 'continue' in R [OK]

Common Mistakes:

• Using 'continue' instead of 'next'
• Using 'skip' which is invalid
• Confusing 'break' with skipping iteration

3. What will be the output of the following R code?

for(i in 1:5) {
  if(i == 3) next
  print(i)
}

medium

A. [1] 1 2 4 5

B. [1] 1 2 3 4 5

C. [1] 1 2 3 4

D. [1] 1 2 3 4 5 3

Solution

1. Step 1: Analyze the loop and condition

   The loop runs from 1 to 5. When i == 3, the next statement skips printing 3.

2. Step 2: Determine printed values

   Values 1, 2, 4, and 5 are printed. The number 3 is skipped.

3. Final Answer:

   [1] 1 2 4 5 -> Option A

4. Quick Check:

   next skips 3, so output excludes 3 [OK]

Hint: next skips printing 3, so output misses 3 [OK]

Common Mistakes:

• Including 3 in output
• Thinking next stops loop
• Confusing output format

4. Identify the error in this R code snippet:

for(i in 1:5) {
  if(i == 4) next()
  print(i)
}

medium

A. The loop variable i is not defined

B. Using parentheses with next causes an error

C. print() cannot be used inside loops

D. The if condition syntax is incorrect

Solution

1. Step 1: Check usage of next statement

   In R, next is a statement, not a function, so it should not have parentheses.

2. Step 2: Identify syntax error

   Using next() causes a syntax error. Correct usage is just next.

3. Final Answer:

   Using parentheses with next causes an error -> Option B

4. Quick Check:

   next is not a function, no parentheses [OK]

Hint: Don't add () after next; it's not a function [OK]

Common Mistakes:

• Writing next() instead of next
• Assuming next is a function
• Misreading error cause

5. Consider the following R code:

sum <- 0
for(i in 1:10) {
  if(i %% 2 == 0) next
  if(i > 7) break
  sum <- sum + i
}
print(sum)

What is the output of this code?

hard

A. 25

B. 20

C. 16

D. 30

Solution

1. Step 1: Understand loop conditions

   The loop runs from 1 to 10. It skips even numbers with next. It stops completely when i > 7 due to break.

2. Step 2: Calculate sum of odd numbers less than or equal to 7

   Odd numbers before break: 1, 3, 5, 7. Sum = 1+3+5+7 = 16.

3. Final Answer:

   16 -> Option C

4. Quick Check:

   Sum odd < 8 = 16 [OK]

Hint: Sum odd numbers until i > 7, skip evens [OK]

Common Mistakes:

• Including even numbers in sum
• Ignoring break condition
• Summing all numbers 1 to 10